It's a sequence of events, an inexorable chain reaction where each small link is fundamental, like a snake of upended dominoes.

NPR: Excerpt: 'The Sister'

In general terms, a change in your genome sequence can mean a small alteration, like removing or adding a single link in a chain, or it can mean a structural change involving bigger chunks, like removing or adding whole sections of the chain.

FORBES: Autism And Genetics: It's Complicated

One example is the polymerase chain reaction (PCR), a standard technique which employs enzymes to churn out millions of copies of a DNA sequence and involves cycles of gentle heating and cooling.

ECONOMIST: Acoustic microfluidics